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In the addition problem above, the number * must be
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20 May 2022, 09:03
20 May 2022, 09:03
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Question Stats:
52% (01:58) correct
47% (01:57) wrong based on 21 sessions
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In the addition problem above, the number * must be?
(A) 5
(B) 6
(C) 7
(D) 8
(E) 9
Part of the project: GRE QCQ & PS 3 Questions Every One DAILY Challenge - (2022)
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GRE Math Essentials for a TOP Quant Score - Q170!!! (2021)
GRE Geometry Formulas for a Q170
GRE - Math Book
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
GRE Math Essentials for a TOP Quant Score - Q170!!! (2021)
GRE Geometry Formulas for a Q170
GRE - Math Book
Re: In the addition problem above, the number * must be
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21 May 2022, 03:13
21 May 2022, 03:13
1
Look at the hundreds digit: it's 2. This means that 7+9+5 + Carry = 22. Carry is definitely 1. The Carry is coming from 4 + * + *.
Thus look in the answer choices that when substituted into 4 + * + * yields a number greater than 10 but lesser than 20. Possible values are 5, 6, and 7.
Substitute one by one and look for whether 4 + * + * is larger than 10 and lesser than 20.
5. Not possible. This does not yield 4 + * + * = ()unit digit of *.
6 Possible. This DOES yield 4 + * + * = ()unit digit of *. Hence 4+6+6=16. Which satisfies the condition that it should be in between 10 and 20.
Thus look in the answer choices that when substituted into 4 + * + * yields a number greater than 10 but lesser than 20. Possible values are 5, 6, and 7.
Substitute one by one and look for whether 4 + * + * is larger than 10 and lesser than 20.
5. Not possible. This does not yield 4 + * + * = ()unit digit of *.
6 Possible. This DOES yield 4 + * + * = ()unit digit of *. Hence 4+6+6=16. Which satisfies the condition that it should be in between 10 and 20.
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Re: In the addition problem above, the number * must be
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21 May 2022, 06:54
21 May 2022, 06:54
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Carcass wrote:
In the addition problem above, the number * must be?
(A) 5
(B) 6
(C) 7
(D) 8
(E) 9
STRATEGY: Upon reading any GRE Multiple Choice question, we should always ask, Can I use the answer choices to my advantage?
In this case, we can easily replace each * with each answer choice until we find the one that creates the correct addition.
Now let's give ourselves up to 20 seconds to identify a faster approach.
In this case, we can also assign variables to the missing digits, but I can already see that testing the values will be super fast.
So, let's go with that...
When we replace each * with 5, the addition doesn't work.
When we replace each * with 6, the addition works!
Answer: B
